Amniotic fluid: Source of trophic factors for the developing intestine

Table 5 Effects of epidermal growth factor on the gastrointestinal tract

Increased effect on	Possible secondary message
Proliferation	-
Bicarbonate secretion	Prostaglandins
NaCl and glucose uptake	Na+- glucose cotransporter, lipids
Mucus secretion	Prostaglandins
GI blood flow	Beta-adrenergic NO prostaglandins
Longitudinal smooth muscle contraction	Prostaglandins
Circular smooth muscle contraction	Desensitizes (not prostaglandins)
Restitution	Cell-migration prostaglandins
Permeability	-
Mucosal protection	Proliferation, polyamines, mucus, trefoil peptides
Decreased effect on	Possible secondary message
Gastric acid secretion	Protein kinase C, cAMP
Gastric emptying	-
Increased and decreased effect on	Possible secondary message
Chloride secretion	Phosphatidylinositol 3-kinase
Pancreatic amylase (3.2.1.1) secretion	cAMP phospholipase C

GI: Gastrointestinal; NaCl: Sodium chloride; cAMP: Cyclic adenosine monophosphate.